I shoot in RAW files. After saving in my computer, I open these with Camera Raw program. Then, after editing them, i save JPG file. After this i open the JPG files in Adobe Photoshop CS6 to edit them a little more. So far, so good. Then I want to resize them in Lightroom because it's much easier and faster than all other programs. After importing them al the JPG files ruin. What should i do to prevent his happening again?

(P.S. 1. The same thing in Bridge after importing them. 2. I think all the effects and filters doubles after import.)